


Break me, Shake me

by Askellie



Category: Undertale (Video Game)
Genre: Fighting Kink, LV Problems, M/M, Sexual Tension
Language: English
Status: Completed
Published: 2020-09-13
Updated: 2020-09-13
Packaged: 2021-03-06 18:01:44
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 2,025
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26443129
Author URL: https://archiveofourown.org/users/Askellie/pseuds/Askellie
Summary: “Life’s not real fair,” Killer countered. “But you know that, right? That’s why you’re here with us.”Cross isn't dealing well with his LV. Fortunately, there's a couple of experts on hand to help him out.
Relationships: Killer/Dust, Killer/Dust/Cross, Kross - Relationship, Sans/Sans (Undertale), dust/cross, killer/cross
Comments: 14
Kudos: 178





	Break me, Shake me

**Author's Note:**

> A little gift for Careless Creativity, who inspired me with their take on this triad. *_*

Dust watched mutely from the edge of the training field as Cross cleaved the training dummy into pieces. His first swing sliced through its brittle neck, a clean decapitation, whilst the second split it in half down the centre, bi-secting it...cross-secting it? Heh. He’d have to tell that one to Killer later. 

Even though his victim was clearly ‘dead’ -- as much as an inanimate object could be -- Cross didn’t switch targets. He continued to hack at the dummy with increasingly wild swings, stuffing and splinters flying everywhere. His grip on the sword hilt was so fierce Dust could see his stressed magic burning between his phalanges, and though Cross’s expression was fixed into a stoic grimace his eyelights were pulsing unevenly; unfocused and uncontrolled. It was a state Dust was intimately familiar with.

Cross was LV9 -- a terrible place to be, in Dust’s opinion. That was about the point where the residual hope and compassion in a monster’s soul was starting to be crushed into paranoia and hatred. Not yet hardened enough by apathy, still soft enough to feel the incessantly crawling of each sin. The EXP felt heavier, almost a physical weight to be carried along with the sickening hunger that came from knowing there was only one way to end the pain.

Unleash it back onto others. 

Back in his own universe, Dust had always made sure to pick a route where he could grind the levels between 8 and 12 quickly and efficiently just to avoid that particular problem. LV12 was easier, safer. By then numbness had properly set in, leaving him with nothing but a calm sense of purpose. 

The best thing to do would be to take Cross out to an AU and let him work off the fury on real monsters instead of fakes, but if the Boss had been on board with that idea it would have happened already. While they were allowed to cause as much mayhem and misery as they liked, killing was off the table. As long as Ink and Error held their stupid truce and the number of worlds Nightmare could draw power from had stagnated. He needed every soul alive and well to draw from their suffering.

Not to mention  _ Cross’s suffering _ was probably keeping the Boss nicely sustained all on its own. Unfortunately it was starting to look like they were going to run out of training dummies before Cross’s fit had run its course. 

A low whistle to his right made Dust startle, his own eyelight sparking dangerously as he turned to glare at Killer. Even Pap didn’t always see Killer coming. Sometimes he was as quiet as a ghost himself, appearing out of nowhere and leaning aggressively into Dust’s personal space. 

“He’s still going, huh,” Killer noted. His inane grin tugged at its corners. “Someone really should do something about that.”

That someone wasn’t going to be Killer, judging from the look on his face. Dust rolled his eyes, but reluctantly pushed himself to his feet. It wasn’t that he cared about their newbie, but letting him fly off the handle would probably make a mess, and undoubtedly Killer would find some way to shift the blame onto Dust even if he was equally complicit in doing nothing to prevent it. That was one of the perks that came with being the Boss’s favourite bitch.

It took longer than it should have for Cross to notice Dust’s approach. He whirled around with a startled jerk, sword raised instinctively. His body was trembling with a combination of tension and exertion, his movements almost stiff and puppet-like. It was almost funny watching him school his expression into cool indifference, like the circle of mutilated dummies around him wasn’t a testament to his slipping control.

“What do you want?” Cross asked gruffly. His tight posture reminded Dust of a puffed up kitten who didn’t know how to defend itself. He'd never found out exactly where Nightmare had dragged Cross from, but it was telling how for the most part their newest member simply did his best to keep out of everyone’s way. He was intimidated, and trying desperately not to show it.

Dust clicked his fingers, summoning up a ring of bones. “Fight me.”

“Really?” Cross sounded surprised. There was a flicker of something in his expression, a flash of excitement that might have been easily mistaken for LV lust, but...no, it was something different. A more honest kind of eagerness, like Cross just enjoyed fighting for its own sake, for the opportunity to test himself.

~~ It reminded Dust of Papyrus.  ~~

Dust didn’t bother answering except in the form of a Blaster. It opened its jaws in a soundless scream and fired, scorching the ground where Cross had been standing just a moment before. Cross was already moving, unperturbed by unsolicited assault. His sword burned red as he lunged towards Dust, the weapon arcing through the air without a shred of hesitation or mercy, forcing Dust to duck nimbly out of its path.

Dust had fought a lot of Sanses. They tend to be careful, methodical fighters, relying on bones and blasters to make up for their inherent fragility. Cross’s style was fast and aggressive, constantly trying to close the distance between them and relying on his blade. It reminded Dust a lot of Killer, though he knew Killer deliberately chose to fight that way because he enjoyed the risk and excitement of a close and personal brawl.

Though there was a shadow of those feelings on Cross’s face too, as well as a swell of growing bloodlust each time the blade tried to slice him. It was lucky that Dust had a wealth of experience in dealing with knife-wielding maniacs. 

A constant hold of blue on the other skeleton’s soul gave Dust the control needed to slow Cross down, the weight of gravity forcing additional labour on each step and strike. Waves of bones added additional obstacles to the battlefield, but Cross was just as quick on his feet, leaping over most of them and simply slicing through the ones he couldn’t. With a seamless shift of his grip he flicked some of the shattered bones back towards Dust, aiming for his face. Dust hissed, swiftly dismissing his magic, already moving to dodge the sword again when his body suddenly swivelled and lurched in the opposite direction he’d intended. It was a move guided entirely by instinct, but it let him dodge the knife that flew between them.

Cross wasn’t so lucky, the thrown weapon tearing a deep line across his humerus as it skimmed past him. He glanced down at the wound, then back up towards its origin where Killer was standing with a beaming smile on his face. He already had another knife in hand as he stepped over one of the desimated training dummies.

Dust scoffed softly. Figures; Killer must have gotten bored just watching from the sidelines. 

“Two on one?” Cross asked, glancing between them. There was a little smirk pulling at his mouth; he seemed to like the idea.

Killer brandished his weapon gleefully. “Yeah, well...Bad guys never fight fair, y’know?”

“Heh,” Cross rolled his shoulders. The painful tension of his LV was starting to leach out of him. He looked much more relaxed, even with the sheen of exertion on his skull. “Figures.”

Dust threw out a complex wave of bones as Killer leapt towards Cross, trusting his long-time partner to remember his patterns and dodge accordingly...or not. A few bruises on his shins would serve him right for that near-miss with the knife. Killer didn’t even look down. He moved with unnatural grace, each step perfect, undaunted, as he closed the distance. It was almost funny, watching him counter Cross’s oversized blade with his own, but despite the difference in size he seemed to have no problem holding off Cross’s strikes. In fact, Cross was the one forced to back up, stumbling between Dust’s bones and blocking far more often than he was attacking.

It hadn’t escaped Dust’s notice that Cross had been relying solely on his sword before, but against two foes all bets were off. Soon the training field was a crossfire of blasters and bone attacks thrown with reckless abandon. Cross was definitely forced to go on the defensive, but he had a few tricks that very nearly worked; somehow commandeering one of Dust’s blasters to fire back at him, whilst nearly landing a hit on Killer with a thrown knife of his own summoned out of the air.

Killer’s delighted laugh belied the vicious way he threw himself against Cross in a full-body tackle that the other clearly wasn’t expecting. He dropped his sword, its form vanishing before it could even hit the ground, landing hard on his back. Immediately, Dust impaled them both through with a wall of cyan bones, forcing them to stay still to prevent the magic from gnawing through their HP.

“Nice,” Killer congratulated Dust, even though he was effectively trapped as well. He was straddling Cross’s waist, one knee planted on Cross’s wrist to keep it pinned down. His knife was poised against Cross’s collarbone, not quite at a good stabbing angle, but close enough to threaten it. “This is the part where we’d kill you.”

Cross let out a shaky breath, staring up at the ceiling. “That wasn’t really a fair fight.”

“Life’s not real fair,” Killer countered. “But you know that, right? That’s why you’re here with us.”

A complicated expression passed over Cross’s face, too quick for even Dust’s eyes to catch. Even now, his mismatched eyelights were still pulsing, the red one burning like a vicious flame and the white one flickering like a globe about to burn out. Dust could still smell the LV on him, simmering just beneath the surface. 

Carefully, he retracted his bones, leaving Killer free to move but Cross still impaled in a few crucial places. When Cross shot him a look, confused and irritated, Dust just smirked at him, kneeling down beside his skull.

“We won,” he said, poking Cross in the nasal bone, earning an amusingly disgruntled huff. “Which means we get a reward.”

“Reward…?” Cross asked suspiciously, then startled when Killer tugged meaningfully at the waistband of his shorts. He tried to flinch away, only to yelp as the cyan magic vengefully bit into his bones. “What-?”

Cross clearly hadn’t had his LV long enough to know that the best way to deal with it, aside from fighting, was fucking. The indignant squeak he made as Killer ground down on him was downright precious, as was the way he stared at Dust with wide sockets, as if expecting him to be scandalised. 

Heh. Like Dust hadn’t seen Killer eagerly sucking someone off in a post-battle high before. He pet Cross’s skull condescendingly. “Don’t worry. You’ll enjoy it too. Killer’s pretty good with his mouth.”

Cross clearly wasn’t expecting an anecdote of personal experience, and his sockets went even wider. Killer snorted. “Flatterer. Just because you’re sweet talking me doesn’t mean I’m going to do you after.”

“I’ll do you,” Dust challenged. “On the floor, right here in the open. You’d like that.”

Killer gave a hum of agreement. Maybe if Dust was still in the mood, he’d follow through on his threat. 

Cross lay still, tense and uncertain. Dust looked at his posture thoughtfully. “If you don’t want it, you can go. These bones aren’t really stopping you if you really want to leave.”

Cross certainly had the HP to soak the damage, and the determination to tell them off if he really wasn’t interested. Cross’s expression was conflicted, but didn’t make any move to escape. Unexpectedly pleased, Dust leaned down and carefully pressed his teeth to Cross’s unresisting mouth. Close up, he smelled like sweat and spice and something strangely sweet, like chocolate. It was an appealing combination. “Or stay. Let us help you burn off some more of that tension.”

“I promise we’ll show you a good time,” Killer agreed, reaching for Cross’s shorts again. This time there was no resistance as he started to tug them down. 


End file.
